Sulpiride is only found in individuals that have used or taken this drug. It is a dopamine D2-receptor antagonist. It has been used therapeutically as an antidepressant, antipsychotic, and as a digestive aid. (From Merck Index, 11th ed)In contrast to most other neuroleptics which block both dopamine D1 and D2 receptors, Sulpiride is more selective and acts primarily as a dopamine D2 antagonist. Sulpiride appears to lack effects on norepinephrine, acetylcholine, serotonin, histamine, or gamma-aminobutyric acid (GABA) receptors.